/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.log4j.lf5.util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Provides utility methods for input and output streams.
 * 
 * @author Richard Wan
 */

// Contributed by ThoughtWorks Inc.
public abstract class StreamUtils {
	//--------------------------------------------------------------------------
	// Constants:
	//--------------------------------------------------------------------------

	/**
	 * Default value is 2048.
	 */
	public static final int DEFAULT_BUFFER_SIZE = 2048;

	//--------------------------------------------------------------------------
	// Protected Variables:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Private Variables:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Constructors:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Public Methods:
	//--------------------------------------------------------------------------

	/**
	 * Copies information from the input stream to the output stream using a
	 * default buffer size of 2048 bytes.
	 * 
	 * @throws java.io.IOException
	 */
	public static void copy(InputStream input, OutputStream output)
			throws IOException {
		copy(input, output, DEFAULT_BUFFER_SIZE);
	}

	/**
	 * Copies information from the input stream to the output stream using the
	 * specified buffer size
	 * 
	 * @throws java.io.IOException
	 */
	public static void copy(InputStream input, OutputStream output,
			int bufferSize) throws IOException {
		byte[] buf = new byte[bufferSize];
		int bytesRead = input.read(buf);
		while (bytesRead != -1) {
			output.write(buf, 0, bytesRead);
			bytesRead = input.read(buf);
		}
		output.flush();
	}

	/**
	 * Copies information between specified streams and then closes both of the
	 * streams.
	 * 
	 * @throws java.io.IOException
	 */
	public static void copyThenClose(InputStream input, OutputStream output)
			throws IOException {
		copy(input, output);
		input.close();
		output.close();
	}

	/**
	 * @return a byte[] containing the information contained in the specified
	 *         InputStream.
	 * @throws java.io.IOException
	 */
	public static byte[] getBytes(InputStream input) throws IOException {
		ByteArrayOutputStream result = new ByteArrayOutputStream();
		copy(input, result);
		result.close();
		return result.toByteArray();
	}

	//--------------------------------------------------------------------------
	// Protected Methods:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Private Methods:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Nested Top-Level Classes or Interfaces
	//--------------------------------------------------------------------------

}
